I haven't seen one yet, but there's certainly an opportunity for someone to build and sell them. It needs Apple-esque aesthetics and quality on the foot, height and rotational adjustment, and should cost noticeably less than $400 (so that it competes with Apple's height-adjustable stand even for those not looking to rotate their display). That option also would give all SD customers the option to choose the VESA version and therefore not be locked into any particular usage scenario in the future.